Apparatus for supplying steam to engines when the main supply is cut off



April 8, 1930.

R. WOOD APPARATUS FOR SUPPLYING STEAM TO ENGINES WHEN THE MAIN SUPPLY IS CUT OFF 2 Sheets -Sheet 1 Filed May 25. 1927 /NVEN Q: (ZarssQr W Apnl 8, 1930. R. WOOD 1,754,184

APPARATUS FOR SUPPLYING STEAM TO ENGINES WHEN THEMAIN SUPPLY IS CUT OFF Filed May 23. 1927 v 2 Sheets-Sheet 2 II \V/ H X /NVENTOIQ Q0 sea-r W00 0 Q 'YMWW M- Patented Apr. 8, 1930- UNITED STATES PATENT OFFICE 1101mm: woon, or eanwrcx, ISLE or MAN APPARATUS FOR SUPPLYING STEAM TO ENGINES WHEN THE MAIN SUPPLY IS This invention relates to apparatus for automatically supplying steam to the cylinders of running engines when the mainsupply of actuating fluid thereto is cut off, and is specially applicable to steam locomotives.

Certain classes of engines have to run tor periods during which the supply of actuating fluid, say steam, is cut ofl from the cylinders, as for example in the case of como- 10 tives when descending along incline, or of winding engines when decelerating; and

during such periods, and at each stroke, a

vacuum is formed in the cylinder; under these conditions the usual lubricating devices, 5 which perform satisfactorily so long as working fluid is being supplied to the cylinders, fail to act efiiciently; moreover, when at the ends of the respective strokes, a cylinder opens to exhaust, air or other gas is drawn into the cylinders through the exhaust passages, and in a locomotive, where the exhaust discharges into the smoke box, the gas thus introduced is highly charged with carbonaceous andgritty impurities, and as a result carbon is deposited on the working surfaces, which are also liable to damage by the gritty materials introduced; and the object of the in- 'vention is to provide an automatic device by the use of which the production of a vacuum in the cylinders of a running engine, when the actuating fluid is cut 0it, is prevented automatically by the supply to the cylinders of low pressure steam.

In applying the invention to the case of a steam engine, a portion of the conduit between the main stop valve and the valve casings of the respective cylinders of the engine may be arranged so as to be subjected to a tempera ture which raises the interior thereof to a temperature well above that of the boiling CUT OFF Application filed May 23, 1927, Serial No. 193,615, and. in Great Britain May 27, 1926.

supply of main steam to be cut oii at the main or regulator valve, and that the engine con tinues to run, either due to inertia of its parts or, as in the case of a locomotive, due to its coasting downhill, it will be seen that, as the pistons and valves of the respective cylinders are now driven, after the manner of an air pump, from the crank shaft, a partial vacuum will be produced in the conduit between the cylinders and the stop valve, and that, accordingly, the pressure at the end of the injection pipe in this conduit will be less than that of the atmosphere on the surface of the supply of water to which the other end of the pipe is connected through the nonreturn valve.

Accordingly the non-return valve will be. subjected to a difference of pressure which will open it, with the result that water will flow from the tank into the said conduit, and as the temperature within the conduit is substantially higher than that of boiling point of water, the said water will instantly be converted into steam which, by the suction in the cylinders, will be conveyed to the cylinders and serve to prevent the introduction into the cylinders of carbon or dirt-laden air from the exhaust, and will also serve to give a cushioning action at the end of each stroke, when the said steam will be compressed, in this way relieving the engine parts from the injurious effect of sudden reversal of stresses in the working parts which takes place when there is no cushioning action.

The lubrication of a locomotive is generally effected by a lubricant supply which depends for its eilicient action upon steam being employed to carry the oil into and distribute it in the cylinders, and the supply of auxiliary steam when coasting ensures that lubricating apparatus oi this type shall act efficiently at such periods.

I have illustrated my invention in the accompanying drawings, in which Fig. 1 is a diagrammatic view, and

Fig. 2 is a side elevation in conventional section showing the application to a 1000- motive fitted with a superheater.

Fig. 3 is an enlarged sectional view of the valve B.

Referring first to Fig. 1

A is a tank containing an adequate supply of water; the tank is connected through a non-return valve B and isolating or stop valve 0 to an injection pipe G which is led through the steam, or water space, and/or where the limits of temperature permit, through the flue space of a boiler D; the injection pipe is then led to the valve chest or the steam engine, the connection-being comveniently made to thesteam supply pipe E of the engine F, the supply of steam to the engine being controlled by the valve G.

Under normal working conditions the valve G is open and there is a steam pressure in the injection pipe C which closes the nonreturn valve B. Shouldthe valve Gr nowbe closed to cut off the supply of steam to the engine Whilst the latter is still running, the vacuum which would then be formed in the engine cylinders relieves the pressure on the non-return valve which thereupon opens so that a water supply is drawn from the tank A through the injection pipe C; the water is converted into steam after the manner of a flash boiler in the portions of the pipe subjected to heat'and is deliveredto the engine cylinders in the form of steam which serves to break the vacuum therein and to relieve the stresses which usually occur when the engine 1 runs without a supply of steam, and ensures the satisfactory action of lubricating means depending for its action upon a supply of steam. V

In Fig. 2, which shows an application of the invention to a locomotive fitted with a superheater; A is the tank which in this case is formed in the tender and carries the water supply for the locomotive boiler which is adapted to be fed through the usual outlet pipe a, flexible coupling a and injector feed pipe H which is adapted to be connected to the usual form of injector for supplying water to the locomotive boiler and is provided with a non-return valve h at the point shown.

A stop valve or cock a is provided on the The injection pipe Cis connected to the pipe H at a point intermediate the flexible coupling a and the non-return valve b and at the other end'is connected to the internal steam pipe (Z at a point close to and on the delivery side of the re ulator valve G. When the regulator valve is closed the vacuum induced in the cylinders relieves the pressure on the non-returnv valve B so that water is drawn from the tank A through the non-return valve B, injection pipe G into the pipe (Z and superheater tubes S, after the manner of a flash boiler, the'water being converted into steam, which is then delivered through pipes such as E to the valve chests and the cylinders f of the locomotive, one of which is shown.

The non-return valve h prevents any reverse flow from the boiler injector when the regulator valve is closed and Water is passing through the pipe C. v

The arrangement of Fig. 2 is given by way of examplein the case of a locomotive fitted with a superheater, and the arrangement of the injection pipe C would be modified in through the superheater tubes, when coasting down a long incline.

Additional in ection pipe connections and control valves may be fitted as required, the

said control valves being, if necessary, operated automatically by the. operation of the regulator valve or other parts controlling the working of the locomotive, the arrangement being such as to ensure that when the engine is running and the main supply of steam cut off, there shall be a flow of water from the injection pipe into a suitably heated portion of the conduit leading to the cylinders, and so that said supply shall at once be cut off when the engine stops, or when the main steam is again supplied to the cylinders.

In the case of locomotives to which superheaters are not fitted, thestealn pipe from the regulator valve would be led for the necessary length through the boiler and would therefore be raised to the temperature of the steam or water in the boiler, in which case the injection'pipe would open into the end of the said internal pipe at or near the regulator end thereof, the water supplied being in this way evaporated before passing to the cylinders.

In the case of a stationary engine, a separate tank, to which a supply of water is ensured, may be provided to supply the injection pipe through a non-return valve, a typical arrangement being shown in Fi 1; and, as stated, the water'in the saidtank may be heated, and a portion of the injection pipe be carried through the Water-space and/or the flue of the boiler.

In the case of engines connected to ordinary boilers with externalsteam pipes, suitable means wouldbe provided for ensuring that a lengtliof the said steam pipe between the stop valve and the cylinders would be subjected to the necessary temperature to ensure the vaporization of the water supplied by the injection pipe; as in the examples described, when the engine stops there is no longer a partial vacuum in the steam pipe into which the injection pipe opens so that the non-return valve on the injection pipe closes; or should the engine continue to run and the main stop or regulator valve be opened, the pressure in the steam pipe rises to that of the boiler pressure, with the result that the non-return valve is closed and the supply of water or the like automatically discontinued.

The non-return valve may be fitted with a spring which will prevent it opening until its opposite sides are subjected to a predetermined ditterence of pressure; or the same result may be obtained by gravity, by arranging the valve spindle vertically, as shown.

It will be seen that the method and apparatus described is very simple; the only moving part being a non-return valve, the action of which can be depended upon at all times; that the action is automatic; and that it is not possible, as is the case in vacuum breakers of the reducing valve type employing boiler steam, for there to be any dangerous accumulation of pressure in the cylinders of a standing engine; that the deposit of carbon and other impurities in the cylinders is prevented, and that the efficiency of the usual lubricat: ing devices is maintained when the engine is coasting.

Having now fully described my invention I declare that what I claim and desire to secure by Letters Patent is 1. In apparatus of the type described in combination; a steam engine; a supply of steam therefor; a conduit connecting the cylinders of the engine to the said steam supply; a valve adapted to close the said conduit; a supply of water always subject to a pressure less than the fluid pressure necessary to actuate the steam engine a non-return valve; an injection pipe, one end of which opens into the said conduit between the cylinders and the said valve, and the other end of which is connected through the non-return valve to the said supply of water, so that when the pressure in the said injection pipe rises above that of the water supply the latter is cut-off from the injection pipe; and heating means for vaporizing the water supplied to the injection pipe after the said water has passed through the non-return valve.

2. In apparatus of the type described, in

combination ;a steam engine; a steam boiler; a fuel furnace in the boiler; conduit connection between the steam space of the boiler and the cylinders of the steam engine; a throttle valve on the conduit connection; a supply of water always subject to a pressure less than the fluid pressure necessary to actuate the steam engine; a non-return valve; an injection pipe, one end of which opens into said conduit connection and the other endof which is connected through the non-return valve to the said supply of water; and heating meansfor vaporizing the water supplied to'the injection p'ipeafter the said water has passed through the non-return valve.

3. The apparatus 01 claim 2 in which heat for the heating means for vaporizing the water supplied to the injection pipe is part of the heat generated inthe furnace of the steam boiler.

4. The apparatus of claim 2 in which heat for the heating means for vaporizing the water supplied to the injection pipe is part of the heat generated in the furnace of the steam boiler and transmitted to the steam in the generator.

5. In combination with the elements of claim 1, a steam superheater the tubes of which are arranged to form part of the conduit connections between the steam space of 6. In apparatus of the type described, the

combination with a locomotive comprising a steam boiler, engine cylinders, conduit connections between the steam space of the boiler and the cylinders, a throttle valve on the conduit connections, and a feed-water supply tank ;of a non-return valve; and an injection pipe, one end of which opens into said conduit connections and the other end of which is connected through the non-return valve to the said feed water supply tank.

7. In combination with the elements of claim 6;-a superheater arranged to form part of the conduit connections between the steam space of the boiler and the steam cylinders; the end of the injection pipe remote from the supply of water being connected to the said conduit connections at a point between the throttle valve and the superheater outlet header, so that when the throttle valve is closed the water passing through the injection pipe tothe cylinders is vaporized as it passesthrough the superheater.

8. In combination with the elements of claim 6 ;means for supplying feed water to the boiler; ancl a pipe connecting said means duit connections betwen the engine cylinders to the feed water supply tank; the inlet end of the injection pipe being connected through the non-return valve to the said pipe at a point between the feed tank and the means for supplying the feed water to the boiler.

9. The combination with the elements of claim 6, a superheater arranged to form part of the conduit connections between the steam space of the boiler and the steam cylinders; the end of the injection pipe remote from the supply of water being connected to the said conduit connections at a point between the throttle and the superheater outlet header so that when the throttle valve is closed the water passing through the injection pipe to the cylinders is vaporized by passing through the super-heater; means for supplying feed water to the boiler; and a pipe connecting said means to the feed-water supply tank; the inlet end of the injection being connected through the non-return valve to the said pipe at a point between the feed-tank and the means for supplying the feed-water to the boiler.

10. In a steam locomotive in combination ;a steam boiler; engine cylinders; con- ;and the steam space of the boiler, comprising a dry-pipe in the boiler steam space; a throttle valve on the said dry-pipe; a feedwater supply tank for the boiler; a non-reconnecting the saidmeans to the feed-water supply tank; a non return valve on the said feed pipe; and an injection pipe, one end of which is connected to the non-return valve on the delivery side thereof, and the other end of which is connected to the dry-pipe.

In testimony whereof I set my hand.

ROBERT WOOD.

turn valve; an injection pipe one end of which a is connected through the non-return valve to the feed-water supply tank, and the other end of which is connected to the dry-pipe.

11. In a steam locomotive in combination;-a steam boiler; a fuel furnace in the boiler; flue tubes in the boiler through which the flue gases from the furnace pass; a superheater the tubular heating surfaces of which are located in some of the said'flue tubes; engine cylinders; pipe connecting the engine cylinders to the outlet header of the superheater; a dry-pipe connecting the inlet header of the superheater to the steam space of the boiler; a throttle valve on the dry-pipe; a feed-water supply tank for the boiler, a nonreturn valve and an injection pipe, one end of which is connected through the non-return valve to the feed-water supply tank, and the other end of which is connected to the drypipe.

12. In a steam locomotive in combination;a steam boiler; a fuel furnace in the boiler; flue tubes in the boiler through which flue gases from the furnace pass; a superheater, the tubular heating surfaces of which are located in some of the flue tubes; engine a throttle valve on the dry-pipe; a feed-water supply tank for the boiler; means for supplying the feed-water to the boiler; a feed-pipe 

